Personally, I am a PC gamer and some of my games include World of Warcraft, Team Fortress 2, and Left 4 Dead 2. You can catch more of my gaming habits here.
I have seen plenty of Twitter discussions using #hashTags and Podcasts that go further into specific games. For example when World of Warcraft's latest expansion: Cataclysm was due for launch, Twitter was inundated with #cataclysm chatter.
The Gaming industry pulls in $10.5 billion in revenue. However online gaming has a niche of it's own. People want to play with others. Subscription based games are very common.